SEOUL, Nov. 2 (Yonhap) — South Korea’s spy agency is analyzing a soil sample collected from around North Korea’s nuclear test site, which Pyongyang demolished in May, lawmakers said Friday.

In a briefing to the parliamentary intelligence committee this week, the National Intelligence Service (NIS) also said it is monitoring North Korean leader Kim Jong-un’s health through a 3-D video analysis program, according to the committee members.

“The NIS has asked outside experts to look into soil that was collected right after North Korea shut down the nuclear test site on May 24,” a lawmaker said.

In May, the North demolished its Punggye-ri nuclear test site in a show of its will for denuclearization. The North has conducted all six of its nuclear tests there, including the latest in September 2017.

When a nuclear test-inducing artificial quake was detected in North Korea, authorities collected traces of radioactive material in the air over the East Sea to get information about the North’s nuclear explosion.

But this method has limitation in exactly grasping the details about North Korea’s nuclear tests.

The spy agency also unveiled a 3-D program designed to scan and analyze the changes of a person’s body, which has been used for years to check Kim’s condition. It demonstrated the process during the committee’s meeting, the lawmaker said.

This photo, provided by North Korea’s state news agency on May 25, 2018, shows North Korea’s demolition of its Punggye-ri nuclear test site on the northeast. (For Use Only in the Republic of Korea No Redistribution) (Yonhap)